-- 首先根据exam_record新增一列finish_time WITH T1 AS (SELECT *, TIMESTAMPDIFF(MINUTE,start_time, submit_time) AS finish_time FROM exam_record), -- 连接T1 和 emp_id,为了将emp_level匹到T1上 T2 AS (SELECT T1.emp_id, E.emp_level, T1.exam_id, T1.finish_time,T1.score FROM emp_info E RIGHT JOIN T1 ON E.emp_id = T1.emp_id),...